On the basis of work already in progress we have planned the following endeavors in the coming year: a) To continue studies on the differential uptake of morphine by cultured neuronal and glial cells obtained from embryonic nervous systems and cultures of glial and neuronal cell lines, differentiated by chemical means (serum free media, aminopterin) and neurons obtained by use of differential sucrose gradients from naive, tolerant and withdrawn rat brains. These efforts are directed toward an understanding of the role of glia in opiate effects on the nervous system. b) Morphine uptake by neuronal and glia cells in cultures that have undergone the paradigms of tolerance and dependence by autoradiographic techniques to elucidate the sites to which morphine is attached in these cells. c) Electrophysiological studies of neural cultures exposed to morphine acutely or for prolonged periods and then withdrawn during the study. These will include extracellular and intracellular techniques. d) Studies of catecholaminergic neuronal cultures that have been exposed to the experimental paradigm of tolerance and dependence of morphine effects. Qualitative and quantitative histofluorometric techniques will be used to study the effects of morphine on the synthesis and uptake of catecholeamines in these cultures during various phases of the paradigm. Bibliographic references: DeBault, L.E. and Waziri, R.: Morphine and nalorphine effects on the uptake of C14-morphine by cultured neuronal, glial and fibroblast cells. Transactions of the American Society for Neurochemistry 5:1:March 10-14, 1974.